In automotive instrument panels knobs are used for manual adjustment of controls or actuators such as for heating and cooling systems or radio systems. If the knobs project from the panel and are rigidly fixed, they provide a potential hazard in the event a person is thrown forward during a crash to strike his head against the panel. In some countries it is required that a fixed knob may project only a limited distance from the panel surface; this requirement makes it difficult to grasp the knob. To overcome this limitation and to make a single knob assembly suitable for all countries, it is desirable to provide an arrangement which permits a knob to extend out from the panel for easy manipulation but allows the knob to collapse toward the panel when subject to an axial force which is lower than that which would cause head injury.